I tried to use the "changeset viewer" plugin and received an error saying that multiple plugins would not be loaded.

[anonymous]

What steps will reproduce the problem?

What is the expected result?

Being able to view changeset history using the plugin.

What happens instead?

I receive an error saying the plugin could not be loaded.

Please provide any additional information below. Attach a screenshot if possible.

URL:https://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2020-11-21 14:56:29 +0100 (Sat, 21 Nov 2020)
Build-Date:2020-11-22 02:30:52
Revision:17329
Relative:URL: ^/trunk

Identification: JOSM/1.5 (17329 en) Mac OS X 10.16
OS Build number: macOS 11.0.1 (20B29)
Memory Usage: 1830 MB / 1830 MB (675 MB allocated, but free)
Java version: 1.8.0_271-b09, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
Look and Feel: com.apple.laf.AquaLookAndFeel
Screen: Display 69733632 1440x900 (scaling 1.0x1.0), Display 188945226 1920x1080 (scaling 1.0x1.0), Display 84042945 1920x1080 (scaling 1.0x1.0)
Maximum Screen Size: 1920x1080
Best cursor sizes: 16x16 -> 16x16, 32x32 -> 32x32
VM arguments: [-Djava.security.policy=file:<java.home>/lib/security/javaws.policy, -DtrustProxy=true, -Djnlpx.home=<java.home>/bin, -Djava.security.manager, -Djnlpx.origFilenameArg=${HOME}/Library/Application Support/Oracle/Java/Deployment/cache/6.0/56/1ee8cfb8-377f244e, -Djnlpx.remove=false, -Dsun.awt.warmup=true, -Djava.util.Arrays.useLegacyMergeSort=true, -Djnlpx.heapsize=NULL,2048m, -Dmacosx.jnlpx.dock.name=JOSM, -Dmacosx.jnlpx.dock.icon=${HOME}/Library/Application Support/Oracle/Java/Deployment/cache/6.0/25/4c122699-697effe2.icns, -Djnlp.application.href=https://josm.openstreetmap.de/download/josm.jnlp , -Djnlpx.jvm="<java.home>/bin/java"]
Dataset consistency test: No problems found

Plugins:
+ Mapillary (1.5.27)
+ apache-commons (35524)
+ apache-http (35589)
+ auto_tools (73)
+ buildings_tools (35640)
+ changeset-viewer (22)
+ continuosDownload (91)
+ graphview (35640)
+ javafx-osx (35458)
+ jna (35458)
+ markseen (14)
+ openqa (0.2.0)
+ osm-obj-info (56)
+ reverter (35640)
+ rex (53)
+ utilsplugin2 (35640)

Tagging presets:
+ https://raw.githubusercontent.com/osmlab/name-suggestion-index/master/dist/name-suggestions.presets.xml
+ /Applications/JOSM-Buddy/assets/presets/heading.xml

Map paint styles:
+ https://josm.openstreetmap.de/josmfile?page=Styles/Lane_and_Road_Attributes&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Coloured_Streets&zip=1
+ https://raw.githubusercontent.com/KaartGroup/Kaart-Styles/master/Kaart-Styles.mapcss
+ https://raw.githubusercontent.com/KaartGroup/Kaart-Styles/master/Overlapping%20Ways.mapcss
- ${HOME}/Desktop/Paintstyle:validator checks/Clingstone/New Test QC.mapcss
- https://raw.githubusercontent.com/KaartGroup/Kaart-Styles/master/Kaart_QC_Quandary.mapcss
- ${HOME}/Desktop/Paintstyle:validator checks/Clingstone/New Test QC.mapcss
- https://josm.openstreetmap.de/josmfile?page=Styles/LayerChecker&zip=1

Validator rules:
+ https://raw.githubusercontent.com/KaartGroup/KaartValidator/master/kaart.clingstone.validator.mapcss
+ /Applications/JOSM-Buddy/assets/validators/forbidden-tag-check.validator.mapcss
- https://raw.githubusercontent.com/KaartGroup/KaartValidator/master/kaart.indonesiaNames.validator.mapcss
- https://raw.githubusercontent.com/KaartGroup/KaartValidator/master/kaart.durazno.validator.mapcss
- ${HOME}/Desktop/Paintstyle:validator checks/Clingstone/kaart.malaysiaNames.validator.mapcss

Last errors/warnings:
- 00285.091 E: https://a.mapillary.com/v3/organizations/O0K377md1CVrVkzGu4PV5z?client_id=UTZhSnNFdGpxSEFFREUwb01GYzlXZzpjNGViMzQxMTIzMjY0MjZm
- 00285.108 W: Region [userProfile_BLOCK_v2] : Problem verifying disk.
- 00285.247 E: java.io.IOException: stream is closed
- 00285.839 E: https://a.mapillary.com/v3/organizations/WWtFcTj2k8RnCLHxd2NQ2u?client_id=UTZhSnNFdGpxSEFFREUwb01GYzlXZzpjNGViMzQxMTIzMjY0MjZm
- 00286.029 E: java.io.IOException: stream is closed
- 01676.406 E: Handled by bug report queue: java.lang.NullPointerException
- 01685.145 W: Warning - <html>JOSM could not find information about the following plugins:<ul><li>auto_tools</li><li>apache-commons</li><li>rex</li><li>javafx-osx</li><li>Mapillary</li><li>graphview</li><li>changeset-viewer</li><li>osm-obj-info</li><li>reverter</li><li>continuosDownload</li><li>utilsplugin2</li><li>markseen</li><li>openqa</li><li>buildings_tools</li><li>jna</li><li>apache-http</li></ul>The plugins are not going to be loaded.</html>


=== REPORTED CRASH DATA ===
BugReportExceptionHandler#handleException:
No data collected.

Warning issued by: BugReportExceptionHandler#handleException

=== STACK TRACE ===
Thread: AWT-EventQueue-2 (46) of javawsApplicationThreadGroup
java.lang.NullPointerException
	at org.glassfish.json.JsonObjectBuilderImpl$JsonObjectImpl.getString(JsonObjectBuilderImpl.java:257)
	at org.openstreetmap.josm.plugins.changeset.util.DataSetChangesetBuilder.processRelationPoint(DataSetChangesetBuilder.java:238)
	at org.openstreetmap.josm.plugins.changeset.util.DataSetChangesetBuilder.buildRelation(DataSetChangesetBuilder.java:227)
	at org.openstreetmap.josm.plugins.changeset.util.DataSetChangesetBuilder.build(DataSetChangesetBuilder.java:89)
	at org.openstreetmap.josm.plugins.changeset.util.ChangesetController.getChangeset(ChangesetController.java:30)
	at org.openstreetmap.josm.plugins.changeset.ChangesetDialog.printMap(ChangesetDialog.java:156)
	at org.openstreetmap.josm.plugins.changeset.ChangesetDialog$1.actionPerformed(ChangesetDialog.java:111)
	at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
	at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2348)
	at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
	at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
	at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
	at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:289)
	at java.awt.Component.processMouseEvent(Component.java:6539)
	at javax.swing.JComponent.processMouseEvent(JComponent.java:3324)
	at java.awt.Component.processEvent(Component.java:6304)
	at java.awt.Container.processEvent(Container.java:2239)
	at java.awt.Component.dispatchEventImpl(Component.java:4889)
	at java.awt.Container.dispatchEventImpl(Container.java:2297)
	at java.awt.Component.dispatchEvent(Component.java:4711)
	at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4904)
	at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4535)
	at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4476)
	at java.awt.Container.dispatchEventImpl(Container.java:2283)
	at java.awt.Window.dispatchEventImpl(Window.java:2746)
	at java.awt.Component.dispatchEvent(Component.java:4711)
	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:760)
	at java.awt.EventQueue.access$500(EventQueue.java:97)
	at java.awt.EventQueue$3.run(EventQueue.java:709)
	at java.awt.EventQueue$3.run(EventQueue.java:703)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:84)
	at java.awt.EventQueue$4.run(EventQueue.java:733)
	at java.awt.EventQueue$4.run(EventQueue.java:731)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:730)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:205)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)